> Is there any way to limit who see a site to people using computers
> located within a relatively narrow geographic area (e.g., city, county)
> when they are using the typical search engines?
The very simple answer is no. That question reminds me of "can I prevent
people from saving images that I display to them?".
Even if you asked search engines (and had their consent) to exclude your
site from search queries outside your region, there is the possibility of
using proxies. Needless to say, no decent (in terms of power) search engine
will cater for your needs so my last sentence is a very hypothetical one.
If you have a local and humble search engine (I have heard of such SE's
targetting a small community of sites only) that only crawls local sites,
then you can add exclusion rules to your /robots.txt file which only allow
that one search engine to use up bandwidth.
Hope it helps,
Roy S. Schestowitz